一个基础问题，谢谢。
echo NULL == false?"true":"false"; //输出true
echo false == '0'?"true":"false"; //输出true
为什么下面会输出false呢？
echo NULL == '0'?"true":"false"; //输出false
PHP中变量是以C语言的结构体来存储的，空字符串和NULL,false都是以值为0存储的。
上面这句话是不是正确的。
------解决方案--------------------
php是种弱类型的语言.
所以当你修改成
echo false == 0?"true":"false"; //输出true
也是成立的，所以不能仅仅靠判断'0'就说他是字符串类型因为你使用的是==
他并不会进行类型比较
如果你要判断字符串的0 应该是
echo false === '0'?"true":"false"; //输出false
------解决方案--------------------
来,和我一起读手册....
http://ca.php.net/manual/en/language.operators.comparison.php
中间Comparison with Various Types表格....
不同类型变量比较,首先要做类型转换,怎么转换就决定了最终的结果....
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